[PHILOS-L] April, 10 | Cyrille Imbert at the Emergence Seminar | UNamur

[Gauvain Leconte-Chevillard]

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Hello everyone!

Sorry for cross-posting.

 

We remind you that the University of Namur's Emergence Seminar is proud to welcome, on Friday, April 10, 2026, from 11:00 a.m. to 1:00 p.m. (CET): Cyrille Imbert (CNRS, Archives Poincaré) : 

Characterizing diachronic non-derivability in terms of P-completeness: advantages and tensions

The seminar is held in English, in person in room L52 of the Faculté des Lettres (rue Grafé, 1, Namur) at UNamur, and remotely via the following link:

Emergence Seminar - Cyrille Imbert | Réunion-Joindre | Microsoft Teams

Title: Characterizing diachronic non-derivability in terms of P-completeness: advantages and tensions

 The literature on diachronic weak emergence typically requires two conditions: (1) novelty, meaning the emergence of new, non-trivial properties or powers, and (2) non-derivability, often understood as a form of in-principle unpredictability. While recent work has extensively explored novelty—e.g., Humphreys’ transformational emergence, Sartenaer’s analyses, and Berenstain’s algorithmically compressible patterns—the non-derivability condition remains comparatively underdeveloped. Philosophers often rely on informal ideas such as computational irreducibility, explanatory incompressibility, or the need to “simulate the process,” typically illustrated by cases like chaotic systems or the Game of Life.

However, these references lack a clear formal explication. Existing proposals are unsatisfactory. For instance, PSPACE-completeness risks empirical emptiness and fails to capture paradigmatic examples like the Game of Life. Chaos theory also does not guarantee irreducible unpredictability, since analytic solutions may still exist. Other notions, such as logical depth or attempts to formalize computational irreducibility, address related but distinct issues and remain theoretically unsettled.

This talk argues that P-completeness provides a more precise characterization of diachronic non-derivability. Informally, P-complete problems require irreducibly sequential computation: even with parallel processing, prediction cannot be accelerated beyond polynomial time. This rigorously captures the idea that certain outcomes can only be predicted by simulating the process itself. Moreover, relevant physical systems—such as fluid dynamics or growth processes—and the Game of Life can plausibly be P-complete.

Finally, adopting P-completeness has philosophical implications: it emphasizes intrinsically sequential processes, shifts the burden of emergence toward novelty, and raises questions about how emergence should relate specific emergent properties to their bases.

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Gauvain Leconte-Chevillard

Il/lui (he/him)

Postdoc Université de Namur - SPiN (Sciences and Philosophy in Namur)

gauvainleconte.carrd.co

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[Gauvain Leconte-Chevillard]

CAUTION: This email originated outside of the University. Do not click links unless you can verify the source of this email and know the content is safe. Check sender address, hover over URLs, and don't open suspicious email attachments.

 

Hello Philos-L members,

 

We remind you that tomorrow the University of Namur's Emergence Seminar is proud to welcome , from 11:00 a.m. to 1:00 p.m. (CET): Cyrille Imbert (CNRS, Archives Poincaré) : 

Characterizing diachronic non-derivability in terms of P-completeness: advantages and tensions

The seminar is held in English, in person in room L52 of the Faculté des Lettres (rue Grafé, 1, Namur) at UNamur, and remotely via the following link:

Emergence Seminar - Cyrille Imbert | Réunion-Joindre | Microsoft Teams

Title: Characterizing diachronic non-derivability in terms of P-completeness: advantages and tensions

 The literature on diachronic weak emergence typically requires two conditions: (1) novelty, meaning the emergence of new, non-trivial properties or powers, and (2) non-derivability, often understood as a form of in-principle unpredictability. While recent work has extensively explored novelty—e.g., Humphreys’ transformational emergence, Sartenaer’s analyses, and Berenstain’s algorithmically compressible patterns—the non-derivability condition remains comparatively underdeveloped. Philosophers often rely on informal ideas such as computational irreducibility, explanatory incompressibility, or the need to “simulate the process,” typically illustrated by cases like chaotic systems or the Game of Life.

However, these references lack a clear formal explication. Existing proposals are unsatisfactory. For instance, PSPACE-completeness risks empirical emptiness and fails to capture paradigmatic examples like the Game of Life. Chaos theory also does not guarantee irreducible unpredictability, since analytic solutions may still exist. Other notions, such as logical depth or attempts to formalize computational irreducibility, address related but distinct issues and remain theoretically unsettled.

This talk argues that P-completeness provides a more precise characterization of diachronic non-derivability. Informally, P-complete problems require irreducibly sequential computation: even with parallel processing, prediction cannot be accelerated beyond polynomial time. This rigorously captures the idea that certain outcomes can only be predicted by simulating the process itself. Moreover, relevant physical systems—such as fluid dynamics or growth processes—and the Game of Life can plausibly be P-complete.

Finally, adopting P-completeness has philosophical implications: it emphasizes intrinsically sequential processes, shifts the burden of emergence toward novelty, and raises questions about how emergence should relate specific emergent properties to their bases.

--

Gauvain Leconte-Chevillard

Il/lui (he/him)

Postdoc Université de Namur - SPiN (Sciences and Philosophy in Namur)

gauvainleconte.carrd.co